A Cooperative Repair Method for a Distributed Scheduling System

For some time we have been studying the is sues involved in job shop scheduling in an envi ronment of cooperative distributed agents none of which has a complete view of the resources available or of the tasks to be scheduled Sched ules produced cooperatively by such distributed agents using constraint satisfaction methods are often not optimal because of the inherent asyn chronicity of the distributed scheduling process the bounded rationality of the scheduling agents and the di culty in completely integrating meta level heuristics into an agent s local scheduling processes This paper describes a modi cation to distributed scheduling in which the loosely cou pled distributed processing methods are supple mented with a tightly coupled parallel repair pro cess We explore the implications on the repair process of a distributed environment in which the designer of the repair algorithm must ad dress issues of agent communication and orga nization We describe a search algorithm and a set of heuristics for guiding the repair process and present some experimental results in the con text of the Distributed ARM an airline resource scheduling system